In general, a metal oxide semiconductor (MOS) field effect transistor (hereinafter, referred to as ‘MOSFET’) has higher input impedance than a bipolar transistor so that the MOSFET has large power gain and includes a very simple gate driving circuit.
Also, since the MOSFET is a unipolar device, it has an advantage of having no time delay caused by accumulation and recombination due to minority carriers while the device is turned-off.
Also, the MOSFET has a structure including an oxide film and a gate poly formed on a semiconductor substrate and source/drain regions formed in the semiconductor substrate to the sides of the gate poly.